This invention relates to a reciprocating compressor for use in an automobile air conditioner or the like and, in particular, to a reciprocating compressor of a structure in which a rear housing is formed at one axial end of a cylinder block and a discharge chamber and a suction chamber are formed in the rear housing at an inner area and an outer area in a radial direction thereof, respectively.
A conventional reciprocating compressor of the type is disclosed, for example, in a Japanese Unexamined Patent Publication (JP-A) No. 189897/1995 and comprises a swash-plate element of an integral structure, as will later be described in detail. Another reciprocating compressor of the type is disclosed in Japanese Unexamined Patent Publication (JP-A) No. 77158/1995 and comprises another swash-plate element formed by a combination of a rotor and a wobble plate as separate components, as will later be described in detail also.
In each of the above-mentioned conventional reciprocating compressors, a gas passage penetrating through a cylinder block is formed between a suction chamber and a crank chamber in order to return a blowby gas leaking from the suction chamber back into the crank chamber.
During operation of each of the above-mentioned conventional reciprocating compressors, centrifugal force is produced following a rotary motion of the swash-plate element. Under the centrifugal force, a lubricating oil present within the crank chamber or contained in the blowby gas is splashed towards an inner peripheral surface of the crank chamber. The lubricating oil thus splashed throughout the crank chamber serves to lubricate various driving elements.
However, the lubricating oil splashed towards the inner peripheral surface of the crank chamber often flows out to the suction chamber together with the blowby gas through the gas passage having an open end formed in the vicinity of the inner peripheral surface. This results in shortage of the lubricating oil within the crank chamber. In the worst case, defective lubrication results in abrasion and seizure of the driving elements.